The oil and gas industry utilizes a procedure known as “snubbing” in which a string of pipe is forced into a wellhole under pressure for various reasons, such as, to remove an obstruction that might exist in the well. In such cases, the wellhole usually has been drilled and a certain amount of casing has been set and blowout preventors or other ram apparatus have been installed at the wellhead to seal around the drill pipe or other pipe strings being inserted into the wellhole. These blowout preventers and ram-type apparatus seal around the string of pipe being snubbed into the well under pressure to prevent the pressurized fluid from escaping around the outside of the string of pipe.
In practice, the body of the individual segments of pipe comprising the string of pipe to be snubbed into the well usually are rack-tested hydrostatically or otherwise prior to use to make certain there are no leaks in the body of the pipe. However, as the connections between the various pipe segments are made-up and snubbed into the well, the connections are usually immediately subjected to high external pressures. The rack testing of the pipe segments will not reveal a leak that exists in a connection between two of the pipe segments. A leak in a connection creates a very hazardous working condition for all personnel involved as high-pressure fluid may flow from the inside of the wellhole, through the leak, upwardly through the string of pipe being snubbed into the well, and out onto the workmen. In addition, if corrective measures are required to correct the leak in a connection between the pipe segments after the string of pipe has been snubbed into the well, such corrective measures are expensive.
The oil and gas industry utilizes a procedure known as the work-over of a well in which a string of pipe is forced into a previously drilled well. The well is “live,” that is, contains fluid under pressure, below a certain depth but because of some obstruction, such as sand or concrete or the like, contains little or no pressurized fluid above that depth. When the tool on the end of the string of pipe breaks through the obstruction, the entire drill string, including the connections between the segments, is subject to the pressures of the well, which pressures can be intense. The same problems described above with respect to snubbing pipe into a completely live well, are applicable to this workover procedure.
A need exists for testable redundant connections for subsea wells that can sustain very high pressures. A need exists for testable redundant connections that can be safely tested in the field at very high pressures prior to use to ensure a good fluid tight connection
The present embodiments meet these needs.
The present embodiments are detailed below with reference to the listed Figures.